A new fern from Porto Rico

VOL. _XVIII, PP.

215-216 OCTOBER 17,1905

PROCEEDINGS

OFTHE

BIOLOGICAL SOCIETY OF WASHINGTON

A NEW FERN FROM PORTO RICO.

BY WILLIAM

R.

MAXOX.

Bypermission of theSecretary oftheSmithsonianInstitution.

The name _{Aspidium Krugii} Kuhn

iscited

by Krug

^at

page 112

of

Engler's Botanische

Jahrbiicher,

volume

_{24, 1897,}

under Aspidium

rhizophyllum, as

having been given

^to

seven numbers

of

Porto Rican _specimens

collected

by

^Sintenis

and

distributed

among

^{various herbaria.}

Apparently Kuhn had _thought

his

plant

distinct;

and

its reference to the

well-known Jamaican A.

rhizophyllum

was _probably due

to thefact that certain ofhis

unpublished

^notes

and manuscripts, which

_largely

formed

the basis of

Krug's paper on West Indian

_ferns,

passed through

the

hands

of

Dr.

_Christ,

and

that the latter's

judgment was

followed.

In naming

a collection of

Porto Rican

ferns

not long ago we

perceived the

Porto Rican _plant

to be readily distinguishable

from

its

near

_ally,

and we _purpose

to so

regard

^it.

The name Aspidium Krugii having been merely

^listed

can not be regarded

as published.

Polystichum

Krugii sp.nov.

Differs from P. rhizophyllum ^{in its} thinner _texture, manifest venation, very

much

shorter _stipes, longer

and

narrower _fronds, pinnae narrower

and

lessobtuse _(theupperones greatlyreduced but mostlydistinct),

and

especially in hav.ing the fructification confined to the greatly elongated (10-12 cm.)^linearcaudate apex

and

thefirstpair^ortwoofminute_pinnae.

41-PROC.BIOL. Soc. WASH., VOL. XVIII, ^1905. (215)

216 May on A New _{Fern from}

Porto Rico.

Type ^{in the} U. S. National Herbarium, No. 40,035, being No. 2240 of Sintenis' Porto Rican _plants; collected at Cayey, October 5, 1885.

The

typespecimen^istheonlyrepresentative in the National

Herbarium

ofthe several

numbers

cited

by

Krug. OtherPortoRican specimens^are: Goll, No. _342,

and

_Heller, Nos. 536

and

6095.

A

_single

Cuban

_plant in the D.C.Eaton herbarium

we

also refer here.

Of

the true P. rhizophyllum*

we have

seen excellent specimens from Jamaica,^the type locality;

and

the illustrationof a Jamaican_plant

by Hooker and

_Grevillef ^is_thoroughlycharacteristicofthese.

The compar

atively shortbroad_taperingapices, as figured, offer a verynoticeable dif ference to the uniformly ^linear long-attenuate extremities of P. Krugii.

The

_{Guadeloupeplant}cited

by Krug

^(1.c.)underrhizophyllum

we

havenot seen.

*Polystichurn rhizophyllum (Sw.) Presl,Tent.Pterid.82.1836..

Polypodium rhizophyllum Sw.^Prodr.Veg.^{Ind. Occ.132.1788.}

Aspidiumrhizophyllum Sw. Schrad. Journ.^Bot.18002^: 31. 1801.

tHookerandGreville,Icones Filicum1:pi. 59. 1829.